A New Energy Star... in 2007

The Silent Front
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IDLE POWER MAX 50~60W?

By all accounts, maximum allowable idle power was the single most controversial issue at the meeting. The reactions were said to be varied from hackles rising at intrusion into the heart of the PC makers' own matters to curious questions about how idle was being defined. The latter question seems almost petty. Idle can be easily defined as when the OS is not working and no one doing any other work with the computer. It is not likely to vary by more than a couple of watts regardless of how exactly it is defined. Still, the reaction of the attendees is significant.

The proposed idle parameter for desktops is 50~60W AC! It's a spec that can be achieved by a very small percentage of PCs currently sold or even assembled by enthusiasts in the US or Canada. It requires not only an efficient power supply but also high efficiency components, particularly the processor, which is still the biggest gas guzzler in a PC.

Among SPCR's own wide range of PCs, including test bench systems, there are only three current units that that meet this idle spec:

#1: Pentium M 2.0 (Dothan) with 1GB ram, ATI 9600XT VGA, Samsung notebook drive with >70% efficiency PSU. (35~40WAC idle)

#2: VIA EPIA M mini-ITX system with 512MB RAM, Samsung 3.5" HDD, DVD drive and >70% efficiency PSU. (30W AC idle)

#3: Shuttle SN95G5 with AMD Athlon 64-3500+ (Winchester), 1GB ram, Matrox G550 VGA, Samsung notebook HDD and >78% efficiency PSU (51W AC idle with Cool 'n' Quiet engaged.)

The processor names are bolded (along with Cool 'n' Quiet) because they are primarily responsible for the low power dissipation of the above systems. There is at least one other processor that belongs in the above list, the Transmeta, a super low power / high computing efficiency device used mostly in notebooks, but also at least in one corporate desktop by NEC and in some high efficiency server by NEC, HP, FIC and others.

The Athlon A64 3500+ Winchester core stands alone in this group as the only "standard" desktop processor, one that's not too far off the mark from the pace set by the burning edge silicon from Intel and AMD. The way this processor achieves low idle power is no secret: Cool 'n' Quiet, a feature migrated from mobile computers where it was first developed to extend battery-life. The adoption of this software won AMD an EPA Energy Star Certificate of Recognition last week for advancing computer energy efficiency.

The good thing is that Intel has finally implemented dynamic idle processor throttling (dropping clock and voltage when not needed) with its latest 600 series (and 570) CPUs in the last few months. Any new CPUs from either company are not likely to come without some kind of built-in cool-me-down-when-resting feature.

Looking over recent roadmaps from both Intel and AMD for the rollout of multi-core processors over the coming year or two, decreases in average CPU and system power may be possible. This is not to say all the new silicon emerging from semiconductor labs will be lower in power dissipation, but that the computing-to-power efficiency will be improved across the range, and this may have a real impact on power consumption. Numerous multi-core technology sessions at IDF mentioned power at parity while performance ramps up ~80% compared to single core. AMD's assessment for the highest TDF in forthcoming dual-core server parts is a mere 5W gain, and we can certainly anticipate performance gains simlar to Intel's.


From IDF presentation, Low Power Technology by Chekhar Borkar and Shu-Ling Garver, Intel

If we make the leap of faith that at least one or the other of either Intel or AMD will release dual-core processors at lower clock speed and power consumption level because they can, and because they will still be more powerful and perhaps cheaper than current single-processor offerings, then reductions in average system and idle power could happen. The viability of the new dual-core systems will depend much on software optimized for multiple core ¬ó multi-core compatibility has to be expanded to a much wider range of software.

THE VIDEO CARD CHALLENGE

Another big hurdle for low idle system power consumption is video cards. Recent ATI and nVidia cards are shown in the detailed power consumption graph below. While the highest cards on the chart reach mid-70W, there's already more than talk of VGA cards in the labs that pull over 150W, and if an overheard conversation at IDF can be believed, even 220W. Regardless of the exact numbers, there is little question that the top ranked gaming cards represent a serious source of power consumption in high end PCs.


This chart was created by Xbitlabs and used with their kind permission.

With graphics processing unit (GPU) thermals and power reaching the level of CPUs, you'd think more effort would be spent in curbing their excesses. Although there may have been some flirtation with dynamic power management management features in the past, these features are noticeably absent from current lineups at ATI and nVidia. This key feature may become mandatory for any gaming system seeking Energy Star approval in 2007.

Note that excellent 2-D performance graphics cards that work well in offices and for most working people actually draw very little power, well under 20W. What this suggests is that if gaming cards and systems represent the cream of the crop, the small percentage of users at the very top willing to pay big dollars for sheer entertainment, then perhaps the focus should shift more towards the middle range where a mix of good 2D graphics, movie performance and some games is enough to keep users happy. Optimizing the performance of such video cards for both performance and low power consumption should be encouraged. To this end, there were calls at the draft meeting for a separate discussion and meeting involving the graphic card manufacturers.

Recent graphics card industry numbers for 2004 released by Jon Peddie Research show clear domination by integrated graphics cards. IGCs claimed 56.1% of the total graphics market, a year-over-year gain of more than three points in share. Interestingly, Intel is ranked as the biggest graphic card maker by virtue of the biggest IGC maker. The total number includes mobile graphics, which held 20.2% share of the graphics market. Only the remaining 23.7% of graphic cards sold in 2004 were discrete cards. ATI and Nvidia together accounted for 97.8% of the discrete graphics market in 2004. The breakdown of higher power discrete cards is not known and no one from either company would return my emails or calls. In any case, if 10% of discrete cards (or 2.37% of the total sold) is >30W, then perhaps the issue is moot. The 2007 Energy Star label simply will not go on gaming machines if gaming cards remain as they are today.



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